The invention relates to machine tools generally, and more particularly to a centering tool for use with drill presses, milling machines and other machining apparatus, to enable efficient and precise centering of a round workpiece with respect to the axis of rotation of a machine's spindle.
V-blocks in a number of different configurations have been used as components or steps in procedures for centering cylindrical workpieces. For example, see U.S. Pat. Nos. 1,093,029, 2,061,718, 2,416,782, 2,556,131, 2,455,024, 3,188,076, 3,345,061, and 3,985,462. All of these previous patents show V-blocks in different forms, usually in connection with machining apparatus. Some of them, such as U.S. Pat. Nos. 1,093,029, 3,188,076 and others show forms of V-block used to help position a cylindrical workpiece along the axis of a spindle of a machine which is to perform an operation requiring centering on the workpiece. However, these involve relatively elaborate equipment and procedure for accomplishing a simple goal. The earlier of these two patents shows a form of double V-block for engaging a cylindrical workpiece between upper and lower relatively moveable V-notches, the upper having a jig bore hole for receiving a specific size of drill bit from a drill press. The centering apparatus and the drill press had to be precisely in registry, or adjusted to be in precise registry, and different-sized jig bore holes would have to be provided depending on the size of the drill bit to be used.
Prior centering devices of this nature have not been as efficient and versatile in use, and as simple in construction as the present invention described below.